Towards the management of transitional waters: assessing the potential of benthic tools

In order to assist decision-makers towards the management of coastal transitional waters, we tested the potential of three benthic indices (AMBI, M-AMBI and BITS) in hundreds stations from Italian CTEs, from the Northern Adriatic to Sardinia. Our study highlights i) a high correlation between AMBI and BITS results, despite the different level of taxonomic identification needed, ii) a high correlation between M-AMBI and species' diversity and richness, iii) that M-AMBI overweights the number of species since in its calculation they are counted twice, iv) that M-AMBI acts as a "diversity-corrected AMBI", and, thus, v) it suffers of the reduction of species number along the transitional gradient. This study suggests that in such environments M-AMBI classification seems unable to capture some peculiarities of benthic assemblages in transitional waters. The unmodified use of these indices might impair accurate assessment of ecological quality status and decision-making on the managers' point of view.